What are the steps to problem solve when all I can get are 503s?

[Jorge Díaz]

Hello,

When I installed Varnish in Solaris 10, I had problems with Ulimit values
that might cause problems connecting to backed.

I had problem with file descriptors ulimit, that it is 256 by default in
Solaris.
Executing "ulimit -n 65536" before launching varnish, solves the file
descriptors problem.

You can also try to configure a probe in backed configuration, that tests if
backend is alive.

backend default {
    .host = "backend-host";
    .port = "8000";
        .probe = {
                .url = "/heartbeat/heartbeat.html";
                .timeout = 10 ms;
                .interval = 2s;
                .window = 10;
                .threshold = 8;
        }
}

Later, in varnishadm you can get backend health with: "debug.health"
command:

varnishadm -T locahost:8800 debug.health

(-T is admin port that must be also in varnishd as parameter. varnishd -T
locahost:8800 )




2010/7/12 Kacper Wysocki <kacperw at gmail.com>

> On Sun, Jul 11, 2010 at 7:54 PM, Jacques <whshub at gmail.com> wrote:
> > I tried using a local server and using a vcl rather than command line
> > parameters to define the backend.  I still only get 503s.  Is there a way
> to
> > better debug Varnish so that I can determine why it can't make a backend
> > connection?
>
> Yup there is a better way to debug. You attach a debugger to the live
> process and watch your own request come in
> http://varnish-cache.org/wiki/DebuggingVarnish
> it's a little hands on but works fine if you have symbols and don't
> mind getting dirty.
>
> A dumb and simple suggestion: can you wget the backend from the
> varnish host? :-)
>
> Still, to me it looks like something quite platform-specific, not so
> simple.
> Do the makecheck tests all run fine?
> Oh, and I have a solaris box here too, my makecheck fails and it looks
> like there is some IPC problem:
>
> #### v1   CLI RX| Unknown request in manager process (child not running).\n
> ---- v1   CLI debug.xid command failed: 101 Unknown request in manager
> process (+++ child not running).
>
>
>
> 0K
>
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